So I have had my English Muff’n for a few years now and have always ran it before my gear with minimal or no distortion just to give the tone that vibe. I recently noticed that the tubes were starting to go bad, and I bought some new onese and dropped them in being careful not to touch the glass with bare hands. I haven’t changed anything else about my set up, and for the first few weeks of usage everything was great. Now there is a buz/hum. Like I said nothing else has changed except when the muff’n is plugged in there is noise. Bad tubes? Help?